Pulley crowning mechanism

ABSTRACT

A mechanism for crowning pulley blanks to the internal configuration of a die shell by means of an expandable resilient press pad that is compressible by such means as hydraulic or pneumatic forces.

Uniled States Patent Guthrie B. Stone Honeoye, NY. 763,723

Sept. 30, 1968 June 29, 1971 Stone Conveyor C0. Honeoye, NY.

inventor Appl No. Filed Patented Assignee PULLEY CROWNING MECHANISM 3 Claims, 3 Drawing Figs.

US. Cl 72/62, 29/159 R Int. Cl 821d 39/08 Field of Search 72/62, 61

References Cited UNITED STATES PATENTS lO/l 912 Bauroth 11/1940 Deboretalr... 3/1947 Hulletal.

3/1955 Mueller FOREIGN PATENTS 2/1929 France 10/1955 GreatBritain Primary Examiner-Richard J Herbst Att0rneys-Clarence A. OBrien and Harvey B. Jacobson ABSTRACT: A mechanism for crowning pulley blanks to the internal configuration of a die shell by means of an expandable resilient press pad that is compressible by such means as hydraulic or pneumatic forces.

PATENTEU JUN29 ran INVENTOR GUTHRIE B. STONE ATTORNEY IPULLEY CROWNING MECHANISM BACKGROUND OF THE INVENTION The invention relates to a mechanism for crowning metallic pulley blanks fabricated from pipe and tubing or the like.

As is well known in the art, pulley members are frequently crowned by providing larger central diameters relative to their end diameters and which serve to improve the tracking of the belt members adapted to travel thereacross by maintaining them in a generally centralized position on the pulley.

A common way employed for crowning pulley blanks is by machining as well as through the utilization of internal expanding dies.

From economic view point the crowning of pulley blanks by machining methods is not considered advantageous for labor cost, machining time involved and material waste all contribute necessary expense which must be a guide in determining the cost of the finished product.

The use of internal expanding dies also has its drawbacks, for form dies being precision made items require the talents of skilled craftsmen which adds considerably to the cost of such items, and their use necessitates greater precision of the pulley blanks used in the forming process.

The pulley crowning mechanism according to the instant invention provides a relatively simple and inexpensive mechanism for crowning pulley blanks and eliminates the costly method of machining as well as utilization of internal expansion dies. It allows for variation in diameter, welds, and imperfections of the pulley blank. By simply compressing a resilient so-called press pad by hydraulic or pneumatic means a pulley blank positioned on said press pad is cold formed to the inner dimensions of a die shell adapted to be supported on said pulley blank.

SUMMARY OF THE INVENTION The pulley crowning mechanism of the present invention includes an actuating rod having a press pad assembled thereon which comprises a plurality of resilient circular members as sembled in contiguous relation on said rod. This press pad is disposed intermediate a pair of spaced circular plate members one of which is fixed on the actuating rod.

In the preferred embodiment, the actuating rod is movable longitudinally by hydraulic forces and the press pad is compressed between the circular plate members to the extent of increasing dimensionally the circumferential surface thereof. A pulley blank is slidable onto the press pad and a die shell having an inner central diameter greater than the inner end diameters thereof is adapted to be positioned so as to completely surround said pulley blank. When hydraulic pres sure is applied the actuating rod moves longitudinally to corn press the press pad and as the circumferential dimension of the latter expands it forces the pulley blank to assume the internal configuration of the die shell.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a view in side elevation of the pulley crowning mechanism according to the invention showing the position of the pulley blank and die shell relative to the press pad prior to compression of the latter.

FIG. 2 is a plan view of the mechanism shown in FIG. 1 showing the press pad in its compressed position and the configuration the pulley blank is caused to assume, and FIG. 3 is a view taken along line 3-3 in FIG. 1 showing integrally formed lug members for assembly and disassembly of the opposed die shell halves.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1 the pulley crowning mechanism according to the invention is identified generally by numeral and includes a supporting base 11 having a vertically disposed press platen l2 fixedly attached to the upper end surface thereof as at 13.

The press platen 12 is provided with four horizontally extending hydraulic cylinders 14 (three only shown in the combination of FIGS. 1 and 2) disposed above the base 11 and each of which includes an actuating rod 15 with the outer ends thereof being adapted to bear against a trunnion 16.

Hydraulic lines 17 and 18 (FIGS. 1 and 2) are arranged to direct hydraulic fluid to each end of the hydraulic cylinders 14 and are interconnected with a symbolically illustrated fourway valve 19, a combined pump and motor 20 and a fluid reservoir tank 21 (FIG. 1).

The trunnion 16 includes a centrally located aperture 22 which is in horizontal alignment with a centrally disposed aperture 23 provided in the press platen 12.

A press rod 24 (FIGS. 1 and 2) assembles in and is adapted to extend through apertures 22 and 23 provided in the trunnion 16 and press platen 12 respectively. That end of the press rod which extends outwardly from the trunnion 16 has a washer 25 and a nut 26 assembled thereon and serves to maintain said trunnion in contact with the ends of the actuating rods 15.

As shown in FIGS. 1 and 2, that portion of the press rod adjacent the central part thereof extends through and beyond the aperture 23 in the press platen 12. This part of the press rod that extends from the press platen 12 is adapted to support the elements for crowning pulley blanks and will now be described in detail.

A pair of circular plate members 27 and 28 are assembled in juxtaposed relation on the press rod 24 immediately adjacent to the press platen 12 and a similar pair of plate members 29 and 30 assemble on said press rod adjacent its end and in spaced relation to said plate members: 27 and 28. A press pad generally indicated by numeral 31 assemblies in the space between the plate members 28 and 29 and consists of a plurality of contiguously disposed resilient circular sheet members 32.

This end of the press rod is threaded as shown at 33 and has a nut 34 assembled thereon a distance sufficient to abut plate member 30.

In FIG. 1 a pulley blank 35 is shown supported by the plate members 27, 28, 29, 30 and the press pad 31 and a die shell generally indicated by numeral 36 is. shown assembled over and supported by said pulley blank.

The die shell 36 has an inner central diameter greater than the inner end diameters thereof and comprises opposed halves 37 and 38. These opposed halves are assembled together by means of bolts 39 and nuts 40 (one only shown in FIGS. 1 and 2) which are caused to pass through aligned apertures 41 pro vided in integrally formed lugs 42 (FIG. 3) disposed about and which extend from the peripheral surfaces of said opposed halves.

In operation, the pulley blank 35 is slid onto and supported by the circular plate members and press pad as shown in FIG. 1. The die shell is then slid over the pulley blank to a centralized position thereon. The hydraulic cylinders are then activated causing the cylinders actuating rods 15 to move the trunnion 16 in the direction of the indicating arrow 43 shown in FIG. 2. This movement moves the press rod 24 in the same direction along with plate members 29 and 30. With plate members 27 and 28 being seated against the press platen 12 movement of plate members 29 and 30 as described is effective in compressing the press pad 31. The press pad is compressed with sufficient force so as to cause the expanding outer peripheral surface thereof to deform the pulley blank to the shape of the internal configuration of the die shell 36.

As shown in FIG. 1, the die shell includes an opening 44 into which a floating pin 45 is placed with the lower end of said pin contacting the outer peripheral surface of the pulley blank. As the pulley blank is charging to the configuration of the internal dimensions of the die shell, the pin rises in the opening 44'arid indicates to the operator when the pulley blank has assumed the desired shape. The opposed halves 37 and 38 of the die shell are then separated-to facilitate removal of the crowned pulley blanki Ielairri:

l. Mechanism for crowning cylindrical metallic pulley blanks which includes a cylindrical die shell adapted to encircle said pulley blank and having an inner central diameter larger than the inner end diameters thereof, a press pad adapted to support said pulley blank and die shell thereon, means for compressing said press pad to expand the outer peripheral surface thereof for cold forming said pulley blank to the configuration of the internal dimensions of said die shell, said die shell including an opening in which a floating pin is placed, said pin contacts the outer peripheral surface of the pulley blank and as the pulley blank is deformed said pin rises in the opening indicating to the operator that the forming operation is completed.

2. The mechanism according to claim 1 wherein said resilient circular sheet members on said actuating rod are located entirely within the pulley blank and disposed intermediate a pair of spaced circular plate members, said means for compressing said press pad includes hydraulic cylinders linked to said actuating rod for moving the latter in a longitudinal direction thus providing the pressure required to crown large thick walled pulleys.

3. A pulley crowning mechanism for forming enlarged diametrical areas in a metal pulley blank comprising a cylindrical die shell constructed of a pair of shell elements having a central diameter larger than the end diameters means releasably connecting the shell elements to enable removal of the pulley blank after the central portion has been crowned, a press pad disposed interiorly of a pulley blank and die shell, said press pad including a centrally disposed rod, a plurality of circular resilient sheet members mounted in contiguous relation on the rod, a pair of plate members mounted diameters, said rod in engagement with the sheet members, means securing one of the plate members to the rod to prevent outward movement thereon, the other plate member longitudinally movably receiving said rod, and means interconnecting said rod and the other plate member to move the rod therethrough and pull the plate rnembers together thereby axially compressing and radially expanding the sheet members, said means including a plurality of hydraulic pressure actuated piston and cylinder assemblies paralleling said rod with the rod disposed centrally of the assemblies with the end of the rod connected thereto for moving the rod and compressing the sheet members. 

1. Mechanism for crowning cylindrical metallic pulley blanks which includes a cylindrical die shell adapted to encircle said pulley blank and having an inner central diameter larger than the inner end diameters thereof, a press pad adapted to support said pulley blank and die shell thereon, means for compressing said press pad to expand the outer peripheral surface thereof for cold forming said pulley blank to the configuration of the internal dimensions of said die shell, said die shell including an opening in which a floating pin is placed, said pin contacts the outer peripheral surface of the pulley blank and as the pulley blank is deformed said pin rises in the opening indicating to the operator that the forming operation is completed.
 2. The mechanism according to claim 1 wherein said resilient circular sheet members on said actuating rod are located entirely within the pulley blank and disposed intermediate a pair of spaced circular plate members, said means for compressing said press pad includes hydraulic cylinders linked to said actuating rod for moving the latter in a longitudinal direction thus providing the pressure required to crown large thick walled pulleys.
 3. A pulley crowning mechanism for forming enlarged diametrical areas in a metal pulley blank comprising a cylindrical die shell constructed of a pair of shell elements having a central diameter larger than the end diameters means releasably connecting the shell elements to enable removal of the pulley blank after the central portion has been crowned, a press pad disposed interiorly of a pulley blank and die shell, said press pad including a centrally disposed rod, a plurality of circular resilient sheet members mounted in contiguous relation on the rod, a pair of plate members mounted diameters, said rod in engagement with the sheet members, means securing one of the plate members to the rod to prevent outward movement thereon, the other plate member longitudinally movably receiving said rod, and means interconnecting said rod and the other plate member to move the rod therethrough and pull the plate members together thereby axially compressing and radially expanding the sheet members, said means including a plurality of hydraulic pressure actuated piston and cylinder assemblies paralleling said rod with the rod disposed centrally of the assemblies with the end of the rod connected thereto for moving the rod and compressing the sheet members. 